Restoration a joint's articular surface following degenerative or traumatic pathology to the osteochondral unit pose a significant challenge. Recent advances have shown the utility of collagen-based scaffolds in the regeneration of osteochondral tissue. To provide these collagen scaffolds with the appropriate superstructure novel techniques in 3D printing have been investigated. This study investigates the use of polyɛ-caprolactone (PCL) collagen scaffolds in a porcine cadaveric model to establish the stability of the biomaterial once implanted.

This study was performed in a porcine cadaveric knee model. 8mm defects were created in the medial femoral trochlea and repaired with a PCL collagen scaffold. Scaffolds were secured by one of three designs; Press Fit (PF), Press Fit with Rings (PFR), Press Fit with Fibrin Glue (PFFG). Mobilisation was simulated by mounting the pig legs on a continuous passive motion (CPM) machine for either 50 or 500 cycles. Biomechanical tensile testing was performed to examine the force required to displace the scaffold.

18 legs were used (6 PF, 6 PFR, 6 PFFG). Fixation remained intact in 17 of the cohort (94%). None of the PF or PFFG scaffolds displaced after CPM cycling. Mean peak forces required to displace the scaffold were highest in the PFFG group (3.173 Newtons, Standard deviation = 1.392N). The lowest peak forces were observed in the PFR group (0.871N, SD = 0.412N), while mean peak force observed in the PF group was 2.436N (SD = 0.768). There was a significant difference between PFFG and PFR (p = 0.005). There was no statistical significance in the relationship between the other groups.

PCL reinforcement of collagen scaffolds provide an innovative solution for improving stiffness of the construct, allowing easier handling for the surgeon. Increasing the stiffness of the scaffold also allows press fit solutions for reliable fixation. Press fit PCL collagen scaffolds with and without fibrin glue provide dependable stability. Tensile testing provides an objective analysis of scaffold fixation. Further investigation of PCL collagen scaffolds in a live animal model to establish quality of osteochondral tissue regeneration are required.

Knee osteoarthritis is a common, debilitating condition. Intra articular corticosteroid injections are a commonly used non-operative treatment strategy. Intra articular hip injection with Ketorolac (an NSAID) has proven to be as efficacious as corticosteroids. No prior study compares the efficacy of Ketorolac relative to corticosteroids for relief of discomfort in knee osteoarthritis. The study design was a single centre double blinded RCT. Severity of osteoarthritic changes were graded on plain film weightbearing radiographs using the Kellgren and Lawrence system. Injection was with either 30mg Ketorolac or 40mg Methylprednisolone, given by intra-articular injection, in a syringe with 5mls 0.5% Marcaine. Pre-injection clinical outcomes were assessed using the Numerical Pain Score (NPS), WOMAC, and Oxford knee scores. Patients' NPS scores were assessed at Day 1 and Day 14 post-injection. An assessment of all clinical outcomes took place in clinic at six weeks. There were 72 participants (83 knees) in the study. No patients were lost to follow-up. Mean age was 62.66 years (Range 29–85). 42 knees received a corticosteroid injection, 41 a NSAID injection. Mean Kellgren and Lawrence score was 3.1. There was no significant difference in pre-injection clinical scores in either group. There was a significant improvement of NPS on Day 1 and 14 in both injection groups(p<0.05). These improved pain scores were sustained at 6 weeks in both groups. WOMAC and Oxford Knee Scores showed a statistically significant improvement in the corticosteroid group. WOMAC scores showed significant improvement in the NSAID group, however these improvements didn't achieve statistical significance using the Oxford Knee Score. Corticosteroid or NSAID injectate are a safe and effective non-operative treatment strategy in the patient with knee osteoarthritis. Ketorolac appears to provide effective medium-term improvement of pain and clinical scores. Further follow-up is recommended to investigate if this trend in sustained.